erica ferrari for cbs news, newtown, connecticut. >> yesterday's public memorial, president obama met privately with families of the victims. >>> the school massacre in connecticut presents a challenge, obviously, for parents and educators. thousands of miles away. the key question: how should we communicate with our kids about it? san francisco's unified school district is one of many all across the bay acknowledging the difficulty educators and students have. mayor ed lee and the superintendent released a statement letting our schools know there will be counselors available today to help anyone deal with trauma and stress. >>> the images of last friday's school shooting across the country hit us at home. psychologists tell us younger children will have the hardest time understanding it all. >> so for those children it's really important to try and limit their exposure to these events, all the news coverage, and to more importantly to reassure to them the safety of their environment. >> older children will have a better understanding. but they will want to know more specifics. dr. be